The present invention relates to joint terminals and a joint connector including such terminals. The invention also concerns a way of establishing connections between the unit terminals which form a joint terminal, and between the joint terminals which form a joint connector. The invention further concerns means for achieving these connections in a flexible way, as a function of the particular type of circuit connection system used.
Joint connectors are sometimes employed for interconnecting the electrical cables which are used in common circuit systems such as grounding lines. FIG. 1 shows a joint connector 1 including a joint connector housing 1a, a connecting bus bar 2 adapted for a desired type of connection and inserted into the joint connector housing, and a connector C fitted into the joint connector housing 1a. The connector C includes terminals 3 previously bound to corresponding electrical cables D.
The construction of the above joint connector 1 has the drawback of requiring too many component parts. Further, various kinds of connecting bus bars 2 and joint connector housings 1a must be available, depending on the type of connector circuit. Moreover, in the above joint connector 1, it is not easy to adapt to the increasing number of connections caused by circuit modifications. In view of the above, a variant joint connector 1xe2x80x2 shown in FIG. 2A has been contemplated and disclosed in Japanese patent application published under No. HEI 8-306451. The variant joint connector 1xe2x80x2 includes a variant connector housing 1axe2x80x2 including terminal enclosures 1bxe2x80x2, into each of which is inserted a connector terminal 3xe2x80x2 such as shown in FIG. 2B.
Such a variant connector housing 1axe2x80x2 includes a multi-stage structure for the terminal enclosures 1bxe2x80x2 (a four-stage structure is shown in FIG. 2A). Partition walls defining these terminal enclosures 1bxe2x80x2 have openings for establishing electrical connections in the vertical direction (in FIG. 2A). The front face 1cxe2x80x2 (left-hand side in FIG. 2A) of the variant connector housing 1axe2x80x2 includes a respective insertion orifice 1dxe2x80x2 corresponding to the position of each terminal enclosure 1bxe2x80x2. The connector terminal 3xe2x80x2 is provided with a first elastic contact member 3axe2x80x2, a second elastic contact member 3bxe2x80x2 and a connector portion 3cxe2x80x2, respectively extending on the top, middle and bottom levels of each connector terminal 3xe2x80x2 (FIGS. 2A and 2B).
When such connector terminals 3xe2x80x2 are inserted into a variant connector housing 1axe2x80x2 such as to form a layer, the first elastic contact member 3axe2x80x2 of the connector terminal 3xe2x80x2 positioned on the lower level is brought into contact with the connector portion 3cxe2x80x2 of the connector terminal 3xe2x80x2 positioned on the upper level. Accordingly, the superposed connector terminals 3xe2x80x2 can be connected without applying connecting bus bars 2 as was the case before. Further, a male terminal 4 may be inserted into each terminal enclosure 1bxe2x80x2 through a corresponding insertion orifice 1dxe2x80x2 provided in the front face 1cxe2x80x2 of the variant connector housing 1axe2x80x2. The male terminal 4 can thus be connected to the corresponding second elastic contact member 3bxe2x80x2 of the connector terminal 3xe2x80x2. Such a configuration makes it easier to respond to the increase of the number of connections to be made.
As mentioned above, the variant joint connector 1xe2x80x2 has increased, to a certain degree, the number of connections to be made compared to the joint connector 1. However, in the variant joint connector 1xe2x80x2, the number of connections is restricted by the number of terminal enclosures 1bxe2x80x2 included in the variant connector housing 1axe2x80x2. As a result, a certain range of connector housing products must be prepared in order to respond to the varieties of circuit types. Further, when the connector terminals 3xe2x80x2 are superposed, connections are made forcibly, even if all the connections are not needed. As a result, the variant joint connectors 1xe2x80x2 cannot be employed in a fully appropriate way.
Further, when mounting a wire harness, sub-harnesses K-1, K-2 and K-3 are first formed by preliminary bundling, as shown in FIG. 3. At this stage, the cable""s end portions T-1, T-2 and T-3, which are envisioned to be led out to another sub-harness, are kept unengaged with the connector of any sub-harness, yielding the so-called xe2x80x9cyet-to-be connected terminalsxe2x80x9d. These sub-harnesses are then subjected to a main bundling using an assembling design board. Consequently, the xe2x80x9cyet-to-be connectedxe2x80x9d terminals must be inserted into the connectors of other sub-harnesses, while performing the main bundling. Such a mounting process impairs assembly efficiency. Usually, the preliminary bundling and the main bundling for a wire harness W/H are carried out in different workshops. As a result, the unengaged, xe2x80x9cyet- to-be connectedxe2x80x9d terminals T-1, T-2 and T-3 contained in the sub-harnesses K-1, K-2 and K-3 tend to suffer deformation or damage during transfer. Such deformation or damage may render it difficult or unreliable to insert these xe2x80x9cyet-to-be connectedxe2x80x9d terminals into another sub-harness connector in a proper way.
The present invention has been contemplated to solve such problems. The invention relates to a joint connector in which sub-harnesses contain no xe2x80x9cyet-to-be connectedxe2x80x9d terminal, and which flexibly responds to the increase in the number of electrical cables to be joined and to possible modifications of circuitry. The invention also contemplates providing joint terminals adapted for such a joint connector.
To this end, there is provided a joint terminal including a plurality of unit terminals, each unit terminal including a stem portion in the form of an elongate strip having first and second faces, and first, second and third side rim portions. At least a first cramping connector extends from the first side rim portion in a direction substantially perpendicular to the first face of the stem portion, the first cramping connector including a first cramping blade portion adapted to be connected to the first electrical cable. At least a second cramping connector extends from the second side rim portion in a direction substantially perpendicular to the second face of the stem portion, the second cramping connector including a second cramping blade portion adapted to be connected to a second electrical cable. Additionally, at least one link portion extends from the third side rim portion on substantially the same plane as the stem portion, and wherein the plurality of unit terminals are arranged substantially in parallel relation to one another over the length thereof, and are bound through the at least one link portion.
Preferably, each aforementioned unit terminal further includes at least one cable holder extending from a side rim portion of the stem portion, and adapted for holding a first electrical cable placed on the stem portion.
In another aspect of the present invention, a unitary connector assembly including the above described joint terminal and an insulator plate fixed therewith is provided. The joint terminal is fixed with the insulator plate such that the at least first cramping connector extends from the first side rim portion in a direction substantially perpendicular to the first face of the stem portion, the first cramping connector including a first cramping blade portion adapted to be connected to the first electrical cable. The at least second cramping connector extends from the second side rim portion in a direction substantially perpendicular to the second face of the stem portion, the second cramping connector including a second cramping blade portion adapted to be connected to a second electrical cable. Additionally, the at least one link portion extends from the third side rim portion on substantially the same plane as the stem portion, and the plurality of unit terminals are arranged substantially in parallel relation to one another over the length thereof, and are bound through the aforementioned at least one link portion. The at least first unitary connector assembly is superposed on the at least second unitary connector assembly, so that the second cramping connector of the at least first unitary connector assembly passes through the orifice of the insulator plate and cramps the second electrical cable, whereby the first electrical cable to be carried on the at least first unitary connector assembly can be connected to the second electrical cable to be carried on the at least second unitary connector assembly. Furthermore, the above insulator plate may include an opening at the position corresponding to that of the aforementioned one link portion.
Preferably, the unit terminal further includes at least one cable holder extending from a side rim portion of the stem portion, and adapted for holding a first electrical cable placed on the stem portion.
In a further aspect of the present invention, a joint connector is provided that includes at least first and second unitary connector assemblies respectively including an insulator plate and a joint terminal fixed therewith, the joint terminal including a plurality of unit terminals, each of which includes a stem portion in the form of an elongate strip having first and second faces, and first, second and third side rim portions, at least a first cramping connector, at least a second cramping connector, and at least one link portion. Additionally, the joint terminal may be fixed with the insulator plate such that the at least first cramping connector extends from the first side rim portion in a direction substantially perpendicular to the first face of the stem portion, the first cramping connector including a first cramping blade portion adapted to be connected to the first electrical cable. The at least second cramping connector extends from the second side rim portion in a direction substantially perpendicular to the second face of the stem portion, the second cramping connector including a second cramping blade portion adapted to be connected to a second electrical cable, the at least one link portion extends from third side rim portion on substantially the same plane as the stem, and wherein the plurality of unit terminals are arranged substantially in parallel relation to one another over the length thereof, and are bound through the aforementioned at least one link portion. Furthermore, the at least first unitary connector assembly is superposed on the at least second unitary connector assembly, so that the second cramping connector of the at least first unitary connector assembly cramps the second electrical cable, whereby the first electrical cable to be carried on the at least first unitary connector assembly can be connected to the second electrical cable to be carried on the at least second unitary connector assembly.
Preferably, each unit terminal further includes at least one cable holder extending from a side rim portion of the stem portion, and adapted for holding a first electrical cable placed on the stem portion. Suitably, the joint connector further includes a housing which contains at least first and second unitary connector assemblies.
Further, in the above joint connector, the insulator plate may be provided with an opening at a position corresponding to that of the at least one link portion, such that the opening can receive a cutting tool for cutting the at least one link portion.
Furthermore, in the above joint connector, the stem portion may include first and second pairs of enlarged side portions with a corresponding first or second pair of cramping blades indented therefrom. The first and second cramping connectors are then formed by bending the first and second pairs of enlarged portions, respectively, so that the first pair of cramping blades face each other, while the second pair of cramping blades face each other.
Further yet, the insulator plate may include a rib portion placed adjacent a side of the first or second cramping connector, opposite the side where the pair of cramping blades is mounted, such that the first or second cramping connector is prevented from flexing when the first or second electrical cable is inserted thereinto.
In the above configuration, an end portion of an electrical cable is placed on each stem portion, clamped by the first clamping connector, and may be fixed by the cable holder. As each stem portion is bound to another through a link portion, the clamped electrical cables are electrically connected to one another. When a first joint terminal, with a first electrical cable clamped by a first cramping connector, is superposed on a similarly prepared second joint terminal, a second cramping connector of the first joint terminal clamps an end portion of a second electrical cable clamped by the second joint terminal. In this manner, the electrical cables clamped by the first and the second cramping connector are electrically connected to each other.
When the above joint terminal is to be fixed on an insulator plate, the former may be insert-molded together with the insulator plate. Alternatively, the stem portion of the joint terminal may be provided with a protrusion, while the insulator plate is provided with a corresponding recess, and the stem portion is flanked on a first or a second face of the insulator plate, so that the protrusion and the recess are fitted. In such a construction, at least those end portions of electrical cables of a sub-harness which are envisioned to be connected to those contained in other sub-harnesses are connected to a first unitary connector assembly by clamping. Thereafter, in the main bundling step, the first unitary connector assembly is superposed to a second unitary connector assembly connected to another sub-harness. Accordingly, the electrical cables of different sub-harnesses are connected to one another through the second cramping connector of a corresponding joint terminal. In this manner, the electrical cables, hitherto remaining for later insertion, can be handled in the final form of a sub-harness, by means of making connections with a unitary connector assembly. Further, while the first and second unitary connector assemblies are superposed, some portions thereof may need no connection therebetween, hence there is no need of using the second cramping connector. In such a case, the end portion of an electrical cable may be clamped such that it does not extend beyond the first cramping connector. The connection through the second cramping connector can thus be cut away selectively.
According to another aspect of the present invention, the housing may include a guide, through which the superposed unitary connector assemblies are positioned and inserted into the housing. Preferably, the housing further includes a locking device, by which the unitary connector assemblies are fixed in the housing, once they are completely inserted therein. The unitary connector assemblies are thus held together, after they have been superposed and the necessary connections have been made therebetween. The mounted unitary connector assemblies can the can be easily fixed at a desire position in a wire harness.
When a connection in a same unitary connector assembly is not needed between the adjacent electrical cables held by the corresponding first cramping connectors, the link portion in the joint terminal is cut out through the opening by using a cutting tool. Various kinds of new circuit settings can thus be responded to very quickly. Further, an electrical cable may be clamped to a joint terminal with unnecessary link portions cut off, before the joint terminal has been fixed to an insulator plate by insert-molding or the like. Unnecessary work steps at the level of the joint terminals can thus be avoided.
Suitably, the height of a rib portion is designed so as to define an available space when the unitary connector assemblies are superposed. By defining this height, a deflection of the cramping blade portion can be avoided, and the cramping connections are made more reliably when the end portions of the cable are clamped by the cramping connectors. Further, when the unitary connector assemblies are superposed and the electrical cables of the superposed unitary connector assemblies are fixed by the cramping connectors, the rib portion can be used as a stopper for regulating the vertical movement.